The main character named Bontaro Heiseiyama goes to Kyoto to save Kayo.
The player can get experience and grow a sumo wrestler. Heiseiyama can perform four special techniques: harite, shiko, buchikamashi and nage. Harite is slapping the opponent's face with an open hand, Shiko creates quake and all the enemies will be damaged, Buchikamashi is charge and it is more powerful than Harite, however it isn't effective against all bosses. Nage is throwing. If the enemy is stopped by his Harite, he can throw.
Before starting the game, the player can choose the difficulty mode (level select): easy or hard. There are five areas, each area has three stages and a boss. In each area, the player has access once to a bonus stage. There are three kinds of bonus stages: Kamizumo, Yubizumo and Udezumo. Yubizumo is Thumbs Wrestling, Udezumo is like Arm Wrestling, and finally Kamizumo is Paper Sumo. When the player clears a stage, a password will be displayed.
After beating the game on hard mode, the player can play on a Super mode. In order to get all the ending text and credits, the game has to be finished in all the three difficulty levels. Each playthrough gets harder and the higher difficulties also pit the player against new enemies as well as giving bosses extra special moves.
Source: Wikipedia, "Sumo Fighter", available under the CC-BY-SA License.